1. Field of the Invention
The present invention relates to an image pickup unit including an objective lens that includes a moving lens, and an endoscope.
2. Description of the Related Art
In order to observe sites that are difficult to observe such as an inside of a living body or an inside of a structure, endoscopes that can be introduced from an outside to the inside of the living body or the structure, the endoscopes including an image pickup unit for picking up an optical image, have been used in, for example, medical fields and industrial fields.
An image pickup unit of an endoscope includes an objective lens via which an object image is formed, and an image pickup device, such as a CCD (charge coupled device) or a CMOS (complementary metal-oxide film semiconductor) sensor, disposed at a plane on which an image from the objective lens is formed.
For example, Japanese Patent Application Laid-Open Publication No. 2008-110061 discloses a shooting unit for an endoscope, the shooting unit including a moving lens and having a function that changes an image magnification (scaling function or zoom function). The shooting unit disclosed in Japanese Patent Application Laid-Open Publication No. 2008-110061 has a configuration in which a moving lens holding barrel that holds a moving lens in an objective lens group is disposed so as to freely advance/retract in an optical axis direction and the moving lens holding barrel is moved by an electric linear actuator so as to advance/retract, the electric linear actuator being provided so as to project at an outer peripheral portion of the shooting unit.